Hydrogeology Research Group

The main research interests of Hydrogeology research group are the groundwater flow and mass transport systems and the baseline characterization of geotechnical, geochemical and hydraulic environments up to several hundred meters depth for the safety assurance of radioactive waste disposal. The results will be applied as supporting researches for Nuclear Regulation on prediction of long-term stability of the geological environments.

Geochemical monitoring in 300m depth tunnel under collaboration with JAEA Mizunami URL.

Geochemical monitoring in 300m depth tunnel under collaboration with JAEA Mizunami URL.


Kazumasa Ito (Group Leader)

Based on the multi-phase, multi-component underground fluid flow simulations, recent research interests are the hydro-mechanical coupling simulation and hydro-geochemical coupling simulation with microbiological effects on the groundwater chemistry. As the application of these simulations, evaluations of the groundwater chemical evolution after the excavation of radioactive waste disposal site, surface subsidence with groundwater flow effects and numerical inversion of hydraulic parameters.

Mikio Takeda (Senior Researcher)

Laboratory experiments to evaluate hydraulic properties of low permeability rocks, research interests are focused on the effective diffusivity evaluation with laboratory experiments and analytical solution model. Recent researches are about the chemiosmotic properties of sedimentary rocks which causes the hydraulic pressure anomalies. The laboratory experiments and analytical solution has been developed to evaluate osmotic parameters, as well as the numerical simulation with osmotic model to evaluate the duration of pressure anomalies and groundwater flow under osmotic pressure anomalies.

Akinobu Miyakoshi (Senior Researcher)

My current research interests focus on groundwater flow and subsurface thermal environment changes caused by human activities such as groundwater development, urbanization and deep underground development. Integrating observation data with model results is an also essential component of my research.  Results of my research are applicable for development sustainable usage of groundwater beneath an urban environment, and I am also conducting evaluation of deep groundwater environment using them.  My attempts can contribute to improvement of groundwater flow prediction which considers climate changes such as global warming.

Tsutomu Sato (Senior Researcher)

I am investigating geochemical characteristics and behavior of hot spring water and groundwater. I hope to reveal groundwater fluctuations due to earthquakes and volcanic eruptions. My main survey fields are Ito and Iwaki Cities, Awaji Island, and Usu and Miyakejima volcanoes.

HP: https://staff.aist.go.jp/mr.sato/index.html

Yuki Tosaki (Senior Researcher)

My current research focuses on the origins and ages of deep groundwater by using the cosmogenic radionuclide 36Cl. Our recent application of the 4He-36Cl coupling approach enables individual dating of freshwater and seawater components in groundwater, which would contribute to the better understanding of the past influence of sea level change on groundwater systems. My research interests also include the application of anthropogenic radionuclides for tracing young groundwater.

Akihiko Inamura (Technical Staff)